Air cushion load translating device including anti-side-slip means



July 2, 1968 E, P. THOMAS 3,390,736

AIR CUSHION LOAD TRANSLATING DEVICE INCLUDING ANTI-SIDE-SLIP MEANSF-iled June 28. 1966 I Q P r r /r 22 2e 58 4o 36 261e FIG.3

wlTNEssr-:s mvllurorzA P 4 mi Eugene P. Thomas MJ/v7@ NBS-SW UnitedStates Patent Office 3,390,736 Patented July 2, 1968 s 39o '136 AinCUSHION Loaf) TizANsLATrNG DEVICE INCLUDING ANrLsrDE-sur MEANS Eugene P.Thomas, Baltimore, Md., assignor to Westingi' house ElectricCorporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed JuneZ8, 1966, Ser. No. 561,284 4 Claims. (Cl. 18o- 119) ABSTRACT OF THEDISCLOSURE Other objects, features and advantages of the invention willbecome apparent from the following detailed description of illustrativeembodiments thereof, when taken in connection with the accompanyingdrawing in which:

FIGURE 1 is a side elevation view, partly in outline and partly insection, of an illustrative embodiment of the invention;

FIG. 2 is a front elevation View, partly in outline and partly insection, of the embodiment shown in FIG. l; and

FIG. 3 is a front elevation view, partly in outline and partly insection, showing an alternate embodiment of the invention.

Referring to the several figures in the drawing, the usual air-cushionload-translating device 10, or ground effect pad, comprises the usualload support member 11, which often takes the form of a flat plate orplatform which is often circular, on which a load 14 is carried,together with air-cushion-providing means 16 to establish afloating-type pneumatic support for the platform 11 and its load 14.Such air-cushion-providing means 16 can take the form, for example, asexemplified in the several figures of the drawing, wherein an airsupport chamber 18 is formed at the center of an annular pressurized airmanifold 20 formed in a diaphragm 22 of resilient material whichdistributes pressurized air admitted through an inlet port* 24 into suchair support chamber 18 by way of a plurality of ports 26 openingradially inward from such manifold chamber atcircumferentially-spaced-apart locations therearound. The diaphragm 22is attached to the bottom of the load support member 11, and uponintroduction of pressurized air into the manifold chamber 20, the `wallsthereof will inflate to cause the ejection of pressurized air into thesupport chamber 18. The effective area of the diaphragm 22 and thepressure of the air in chamber 18 is such that the platform 11, or loadsupport member, is caused t float under the iniiuence of such pressuresuch that the diaphragm has a clearanceway 2S of a fraction of an inchabove the surface 30 along which the device is to move. During suchlevitation of the device, air admitted to the support chamber 18 willescape by way of the clearanceway 28 between the wall of the air supplymanifold 20 and the iioor or ground surface 30, which air iscontinuously made up by air admitted via the inlet port 24 to such airmanifold. Such support is frictionless, as is desirable, but normallyaffords freedom of movement for the translating device in all horizontaldirections, and this introduces an element of dificulty in steering andpositioning such device in view of susceptibility to side-slip,particularly where the surface 30 is sloped somewhat.

Upon termination of supply of pressurized air to the air manifold 20 andopening of such manifold to the atmosphere by means (not shown), such asshutting down a motor-operated blower, the load support member 11,including its load, lowers onto the fioor, bringing the infiatablediaphragm into contact therewith and collapsing the walls of themanifold 20 under inliuence of the load 14 and the weight of the loadsupport member 11 to the extent of lowering permitted such supportmember, In FIGS. 1 and 5 the extent of such lowering is defined bydownwardly extending reposesupport means 34 which, in the case where theload support member is circular in plan, such repose-support means 34may take the form of an annular skirt extending downwardly around thecircumference thereof. In other cases the repose position of the loadsupport member can bedefined in any one of numerous other ways.

In accord with the prime feature of the present invention, theair-cushion load-translating device 10 is provided With guide wheelmeans 36 urged by yieldable wheel biasing means 38 into rollingengagement with the surface 30 along which the device 10 is to betranslated. Such wheel means 36 is so arranged as to afford guidabilityof the device and sufficiently biased by the yieldable wheel biasingmeans to provide a sufficient degree of frictional lresistance tosidewise sliding movement as to offset the tendency for lateral movementof the device. The guide wheel means 36 so urged against the floor orground surface 30 tends to -give some support to the load support member11, however, it is intended that primary support of the load 14 and thesupport member 11 be afforded by the air-cushion-providing means 16, andaccordingly the yieldable wheel biasing means urging the guide wheelmeans 36 into engagement with the floor surface 30 affords onlysufiicient force to satisfactorily obtain resistance to lateral movement0f the device without contributing significantly to support of the load14.

In the FIG. 1 and FIG. 3 embodiments, the guide wheel and anti-side-slipmeans 36 takes the -form of a single wheel 40 disposed beneath thesupport member within the air support chamber 18 and in contact with theground or floor surface 30 in alignment with the vertical axis 41passing through the center of gravity of the device inclu-ding the load14. In FIG. 1 the wheel 40 is rotatable on an axle carried by a yoke`arm 42 pivotally supported at one end of a vertical post 44 attached toand extending downwardly from the bottom of the load support member 1'1.Such axle-carrying yoke member is biased downwardly by a helicalcompression spring 46 interposed between the opposite end of such yokemember 42 and the bottom of the support member to urge such a yokemember downwardly about its pivot point at the post 44, thereby actingas a yieldable wheel biasing means urging the wheel into rolling andlateral-wise frictional engagement with the iioor surface 30. The yokemember 442 has freedom for pivotal movement in a vertical plane aboutits pivotal -connection with the post 44, but is not free to move in ahorizontal direction. Accordingly, a force exerted on the load duringlevitation of the device by pressurization of the air support chamber118 in the direction along which the wheel is free to roll affords noopposition to such movement. Sidewise effort directed to the device 10tending to move same along the axis of the wheel 40, however, is opposedby the frictional engagement of such wheels with respect to its beingslid sidewise over such surface. Turning movement of the device 10,however, meets with very little opposition, inasmuch as the device V10is free to swivel about the point of contact of the wheel 40 with theiioor surface 30 which can be at the center of the device. The force ofthe spring 46 can be made adjustable, such as by providing springs ofdifferent 3 pick-up value to suit the weight conditions of the loadaililiated with the device.

In the embodiment shown in FIG. 3, the yieldable wheel biasing means 38takes the form of an air spring and comprises a central portion 50 ofthe diaphragm 22 which is subject to pressurized air from inlet port 24prior to transferral to the air manifold 20' via pressurereducingorifice means 52. Such portion 50 creates a downward force which istransferred to the wheel 4t) via a diaphragm follower means 56 andattached wheel-andaXle-carrying arms 5S.

Having now described the invention, I claim:

1. A pneumatic ground eiect load translating device for substantiallyfriction free movement along a surface thereunder, comprising aload-supporting member, aircushion-providing means adapted to receive aflow of air at superatmospheric pressure and cooperable with suchsurface to derive a pneumatic levitating support for the member and itsload, a single guide wheel, means mounting said guide wheel on saiddevice for rotation about a horizontal axis and cooperation with theaforesaid surface in vertical alignment with the center of gravity ofthe device so as to afford readily guidable non-side-slip movementcharacteristics to the device, and yieldable bias means between saidmounting means and said loadsupporting member and reactive therebetweento yieldably urge said guide wheel into rollable anti-side-slipfrictional engagement with said surface.

2. The ground eiect load translating device of claim 1, wherein said.air-cushion-providing means comprises a resilient annular air manifoldencircling a central air support chamber into which such manifoldempties, and said guide wheel is disposed at the center of said centralair support chamber.

3. The ground effect load translating device of claim 1, wherein saidyieldable bias means is in the form of an air spring availed of air atsuperatmospheric pressure 4conjointly with supply thereof to saidair-cushion-providing means.

4. The device of claim 3, wherein said air spring is availed of suchpressurized air while enroute to said air support chamber, andpressure-drop-providing means are interposed in such air iflow route.

References Cited UNITED STATES PATENTS 3,161,247 12/1964 Mackie3,173,510 3/1965 Smith. 3,216,518 11/ 1965 Beardsley. 3,246,712 4/1966Mackie. 3,263,764 8/1966 Bertin.

A. HARRY LEVY, Primary Examiner.

